The kraft paper used to make Kraft Paper Boxes often undergoes special treatments, which are mainly to meet different usage requirements and improve the performance of the paper box.
1. Waterproof treatment
In some cases, the Kraft Paper Box may need to be exposed to a humid environment, such as packaging some products that may encounter rain during transportation, or used for storing items in a humid environment. At this time, the kraft paper will be waterproofed. The common waterproofing method is to apply a waterproof coating on the surface of the paper, such as a wax coating or a polymer coating. The wax coating can make the kraft paper have good waterproof properties, such as the Kraft Paper Box used to package fresh food. This coating can prevent moisture penetration and extend the shelf life of the food. The polymer coating is more durable and can effectively block moisture without affecting the flexibility of the paper.
2. Moisture-proof treatment
Moisture-proof treatment and waterproof treatment have certain similarities, but they focus more on preventing the influence of moisture in the air on the items inside the paper box. The commonly used method is to add a moisture-proof agent during the production process of kraft paper. These moisture-proof agents can be adsorbed between paper fibers, and when the humidity in the air increases, they will prevent water vapor from condensing inside the paper. For example, for some electronic product packaging Kraft Paper Box, moisture-proof treatment can prevent damage to the product due to moisture.
3. Oil-proof treatment
If the Kraft Paper Box is used to package oily products, such as fried foods or cosmetics, it needs to be oil-proofed. One way is to apply surface sizing to the kraft paper, using a special oil-proof glue to form an oil-proof film on the surface of the paper. This oil-proof film can prevent grease from penetrating the paper and maintain the appearance and strength of the paper box. In addition, it is also possible to use a composite method to combine oil-proof plastic film with kraft paper, which can not only achieve a good oil-proof effect, but also increase the toughness of the paper box.
4. Strengthening treatment
In order to make the Kraft Paper Box more durable, the kraft paper will be strengthened. For example, the strength and tear resistance of the paper can be improved by impregnating resin. Alternatively, multiple layers of paper can be used in a composite manner, where different layers of paper can perform different functions. For example, the outer layer of paper can be used for aesthetic design, while the inner layer of paper focuses on strength and product protection.
